This invention relates in general to protective covers and, more particularly, to a protective cover designed to prevent accidental damage of transformer terminals and coil winding connections during handling and installation of the transformer.
In modern telecommunication systems, voice transmissions between a central office telephone switching system and a subscriber are normally accomplished via an electronic interface known in the art as a subscriber line card. The voice transmissions are coupled to a subscriber line via a line circuit which includes an audio frequency transformer.
In order to mount many line circuits to the above-mentioned subscriber line card, the line circuit transformers have been miniaturized. However, the miniaturization of the transformer has necessitated the use of components, such as coil wires and terminals, of such small physical size and dimension that forces as small as 2.3 lbs exerted on the transformer terminals are sufficient to cause the transformer terminal ends to deflect and the coil winding connections to break. This results in an intermittent connection at the point of attachment of the coil windings to the transformer terminal. This intermittent connection between the transformer terminals and coil windings manifests itself to the subscriber as call cut-off, intermittent transmission loss and voice fading, severely impacting the reliability and quality of the telecommunication service provided to the subscriber.
The displacement of the terminals with the subsequent damage of the coil winding lead wires has been found to occur from incidental contact with human fingers during manufacturing, handling and cleaning of the transformers. Additionally, displacement of the terminals may occur during manufacture by a misalignment of the transformer in assembly fixtures.
It therefore becomes the object of the present invention to provide a protective cover which can be easily fitted to the transformer thereby protecting the terminals of the transformer from external forces which may damage the lead wires of the transformer.